1. Field of the Invention
The present invention relates to organic light emitting diodes (OLEDs) and methods of manufacturing the same.
2. Description of the Related Art
Organic light emitting diodes (OLEDs) are self-emissive displays that may be lightweight and thin, and fabricated by simple processes using simple components. Also, OLEDs have high resolution and wide viewing angles, and can embody complete moving images with high color purity. In addition, OLEDs have appropriate electrical characteristics for mobile display devices because OLEDs consume little power and drive at low voltages.
In a conventional OLED, a pixel electrode is provided, an organic layer including an emission layer (EML) is disposed on the pixel electrode, and an opposite electrode is disposed on the organic layer.
To facilitate the transfer of holes and electrons from the pixel electrode and the opposite electrode to the EML, the organic layer may further include at least one layer selected from hole injection layers (HILs), hole transport layers (HTLs), and electron blocking layers (EBLs) between the pixel electrode and the EML. In addition, the organic layer may further include at least one layer selected from hole blocking layers (HBLs), electron transport layers (ETLs), and electron injection layers (EILs) between the EML and the opposite electrode.
However, the ETL is typically formed of a single organic material. As a result, the OLED including the ETL needs to drive at a high driving voltage and consume a large current, imparting poor luminous efficiency and insufficient lifespan. Therefore, high quality OLEDs are difficult to achieve.